关键词: 移动计算,代理,语义缓存,一致性验证,写延迟 中图法分类号TP311文献标识码A

Abstract: Callback algorithm is a cache management method which is driven by server,but there are some problems in this approach such as writing delay,and cached data needs to be revalidated when network is reconnected．This paper proposed a novel semantic cache scheme using agent technology to check cache consistency．Firstly,the Client/MSS/Server architecture was presented and the functions of agents were given．Secondly,we discussed cache consistent checking method which is aroused by data query operations from terminals and write operations from server．Using agents to manage terminal’s local cache data records and forward server’s invalidating data,this scheme can not only satisfy terminal’s disconnection,but also reduce writing delay time,and maintain cache strong consistency．The results of experiments show that the proposed cache maintenance method can speed up the query response time and overcome the disadvantage of callback algorithm mentioned above,thus is better adapted for the frequent mobility and disconnect network environments.

Key words: Mobile computing,Agent,Semantic cache,Consistency checking,Write delay